Internal combustion engine with sound-proofing casing

ABSTRACT

An internal combustion engine having a sound-proofing casing comprising at least one spaced bottom portion raised sump-fashion and surrounding the engine and attached to the latter by means of sound-proofing supporting members attached to the engine in its bottom-most area, the spaced bottom portion of the casing being closed on top by means of a cover.

United States Patent 1 1 1111 3,796,280 Thien et al. [451 Mar. 12, 1974[54] INTERNAL COMBUSTION ENGINE WITH 3,601,101 8/1971 Thien etal 181/331 SOUND-PROOFING CASING [75] Inventors: Gerhard Thien; Heinz Fachbach;

- Primory ExaminerStephen J QTomsky 2:22;: k all of Graz AssistantExaminer-Vit W. Miska 1 Attorney, Agent, or FirmWatson, Cole, Grindle &[73] Assignee: Hans List, Graz, Austria Watson 22 Filed: Sept. 1, 197221 Appl. No.: 285,772

[30] Foreign Application Priority Data ABSTRACT.

Sept. 3, 1971 Austria 7715/71 An internal combustionv engine having asound- [52] US. Cl 181/33 K, 181/33 G, 123/41.7, proofing casingcomprising at least one spaced bottom 123/198 E portion raisedsump-fashion and surrounding the en- [51] Int. Cl. 1304b 1/99, GlOk11/04 gine and attached to the latter by means of sound- [58'] Field ofSearch 181/33 K; 123/41.7, 198 E proofing supporting members attachedto. the engine 3 in its bottom-most area, the spaced bottom portion of[56] Refe en e Cited the casing being closed on top by means of a cover.

UNITED STATES PATENTS 3,684,053 8/1972 Fachbach en a] 181/33 K 6 Claims,3 Drawing .Figures I II PATENTEB 2 I974 SHEET 2 0F 3 PIC-7.2

INTERNAL COMBUSTION ENGINE WITH SOUND-PRQOFING CASING This inventionrelates to an internal combustion engine with a sound-proofing casinglocated in spaced relation to, and around the outer engine surfaces, andconnected with the engine in such a manner as to absorb such sounds asare conducted through solids. In an internal combustion engine of thistype the oil sump which is raised as far as above the crankshaft centerand attached with its upper border to a laterally spaced supportingflange of the crankcase in such a manner as to absorb sound conductedthrough solids, provides a sound-proofing casing for the engine joinedby soundabsorbing metal sheet mounted on top on each side of thecylinder block, whereas the bottom portion of the oil sump is designedas a spacious oil container. The crankcase of this known type ofinternal combustion engine is so adapted as to provide an open-workedsupporting framework carrying the crankshaft bearings, the raised oilsump forming the oil-wetted outer wall of the engine.

It is the purpose of the present invention to provide an internalcombustion engine of the type hereabove described having asound-absorbing casing, and distinguishing itself by a particularlyplain design and a construction facilitating assembling work, with anencasing producing a high degree of sound-absorption. According to theinvention, the casing comprises a bottom portion raised sump-fashion andhaving a self-contained lateral aperture for the passage of thecrankshaft, the said bottom portion being attached to the cylinder blockby means of at least two supporting members isolating sound conductedthrough solids and located at bottom level for instance, and closed ontop by means of a cover, preferably with an upper portion rigidlyattached to the bottom portion.

By the allround encasement of the internal combustion engine anastoundingly high degree of effective attenuation of engine noise isobtained by very simple structural means as compared with engines havingonly part of their outer surface properly sound-proofed. Since as arule, two or three soundproofing supporting members are amply sufficientfor the attachment of the casing to the engine block, the assembly ofthe engine and the casing is particularly easy. Moreover, these partsare interconnected only over relatively small cross-sections.

Since the portions constituting the casing assembly are very plain andpreferably flat structural elements, it is possible for them to beshaped in such a manner as to facilitate their manufacturing process. Itis furthermore, possible to sound-proof internal combustion en gines bymeans of the encasing according to the invention at a later stage, asrequired.

According to a preferred embodiment of the invention the bottom portionof the casing terminates approximately at the level of the upper edge ofthe cylinder head with a directly adjoining flat cover. This design,equally applicable both to internal combustion engines with a solid andwith an open-worked crankcase, distinguishes itself by its particularsimplicity, since the casing essentially comprises two structuralelements only.

According to another feature of the invention as applied to an internalcombustion engine having a casing comprising a lower and an upperportion, the space between the casing and the engine can be divided intotwo chambers sealed off against each other, the chamber enclosed by thebottom portion of the casing being oilwetted and the other chambersurrounded by the upper portion of the casing kept free from oil andcontaining all auxiliary appliances of the engine. Consequently, the twoencased chambers each have entirely different functions since the bottomportion of the casing acts as an oil-wetted outer wall of the engine,while the upper portion of the casing serves exclusively for thesoundproofing of the cylinder head area of the internal combustionengine and its auxiliary machines.

According to a further embodiment of the invention the bottom portion,and occasionally, also the upper portion of the casing are each of onepiece and preferably made of synthetic material. This type can bemanufactured at extremely low cost.

However, it is also possible according to the invention, to produce thelower portion of the casing by combining two or more members inseparablyinterconnected, preferably by welding, in such a manner as to provide anoil-tight seal. The bottom portion of the casing comprising a pluralityof constituent parts is particularly suitable for use in internalcombustion engine of large external dimensions.

Further details of the invention will become apparent from the followingdescription of two embodiments of the invention with reference to theaccompanying drawings wherein FIG. 1 is a diagrammatic cross-section ofa first internal combustion engine according to the invention on line IIof FIG. 2,

FIG. 2 is a diagrammatic longitudinal section through the engine on lineII-II of FIG. 1, and

FIG. 3 is a diagrammatic cross-section through a modified form of asound-proofed internal combustion engine according to the invention.

The schematically illustrated internal combustion engine shown in FIGS.1 and 2 comprises a soundproofing casing enclosing the engine I with thefuel injection pump 2 and the rest of the auxiliary machines in spacedrelation. I

The casing consists of a bottom portion 3 with its walls raisedsump-fashion, terminating approximately at the level of the upper edgeof the cylinder head Sand provided at its upper border with a circularmounting flange 6.

The bottom portion 3 of the casing has a selfcontained lateral aperture7 for the passage of the crankshaft or of the flywheel flange 8 of theinternal combustion engine 1. The bottom portion 3 of the easing isfurthermore provided on one of its sidewalls 4 with an aperture whichcan be tightly closed by means of a removable cover 9, through whichaccess can be gained to the fuel injection pump 2.

On top, the bottom portion 3 of the casing is closed by means of anessentially flat cover 11 screwed to the mounting flange 6 of the bottomportion 3 of the casing with the interposition of a gasket 12.

The encasing is attached to the engine block by means of a number ofsound-absorbing supporting member 13, two of which engage the bottommostpart of the bottom portion 3 of the casing. The third supporting member13 engages the sidewall 4 of the bottom portion 3 of the casing oppositethe fuel injection pump 2 on the one hand, and the crankcase sidewall 16of the engine by means of a bracket 15, on the other hand.

Both the bottom portion 3 of the casing and the covers 9 and l 1 can bemade from either a synthetic material or from sheet steel or light-metalcasting. In the embodiment shown the bottom portion 3 of the casingcomprises two half-shells tightly interconnected by welding along theirborders l7.

In order to prevent the passage. of sound in the area around theflywheel flange 8 and the inlet connection 18, the casing is providedwith rubber sleeves 19 and 20, respectively.

The design according to FIG. 3 differs from the embodiment hereabovedescribed mainly insofar as the sound-proofing easing of the internalcombustion engine 1' comprises a bottom portion 3 and an upper portion21 rigidly connected with the former, and the cavity between the casingand the engine 1 is divided into two chambers 22 and 23 sealed offagainst each other. For that purpose, a partition 24 is provided between.the bottom portion 3 of the casing and its upper portion 21. Thispartition is attached to a flange 26 of the crankcase with theinterposition of a soundabsorbing gasket 25.

The lower chamber 22 is oil-wetted, which means that the bottom portion3' of the casing forms the oiltight outer shell of the internalcombustion engine 1, whereas the upper chamber 23 is kept free from oiland contains in addition to the fuel injection pump 2 also the rest ofthe auxiliary units of the internal combustion engine.

The various conduits not particularly shown in the drawings, for thesupply of cooling water, fuel and oil can be sound-proofed in a mannerknown per se by the interposition of sound-absorbing elements such ascorrugated tubes, fabric hoses and the like.

I claim:

1. An internal combustion engine with a soundproofing casing arranged inspaced relation to the outer surfaces of the engine and connected to theengine in such a manner as to absorb sound conducted through solids,said casing comprising a troughlike lower casing portion having a bottomand sidewalls, one of the sidewalls having a self-contained aperture forthe passage of a crankshaft, an upper casing portion arranged upon saidtroughlike lower casing portion and rigidly attached to same, a coverplaced upon said upper casing portion and closing the casing, at leasttwo soundproofing supporting members mounted on the said troughlikelower casing portion which is attached to the cylinder block by means ofsaid sound-proofing supporting members, a cavity defined by the casingand the outer surfaces of the engine, two chambers sealed off againsteach other within said cavity, the first of said chambers being enclosedby said trough-like lower casing portion and oil-wetted, the second ofsaid chambers being surrounded by said upper casing portion and keptfree from oil and auxiliary machines arranged on the engine within saidsecond chamber.

2. An internal combustion engine as in claim 1, wherein said bottomportion terminates approximately on the same level as the upper edge ofthe cylinder head, with the directly adjoining said cover beingessentially flat.

3. An internal combustion engine as in claim 1, wherein said bottomportion of the casing and said upper portion of the casing each are madeof one piece.

4. An internal combustion engine as in claim 6, wherein said bottomportion of the casing and said upper portion of the casing are made ofsynthetic material.

5. An internal combustion engine as in claim 1, wherein said bottomportion of the casing comprises a number of structural elementsinterconnected inseparably and in a manner providing an oiltight seal.

6. An internal combustion engine as in claim 5, wherein said structuralelements are tightly interconnected by welding.

1. An internal combustion engine with a sound-proofing casing arrangedin spaced relation to the outer surfaces of the engine and connected tothe engine in such a manner as to absorb sound conducted through solids,said casing comprising a troughlike lower casing portion having a bottomand sidewalls, one of the sidewalls having a self-contained aperture forthe passage of a crankshaft, an upper casing portion arranged upon saidtroughlike lower casing portion and rigidly attached to same, a coverplaced upon said upper casing portion and closing the casing, at leasttwo sound-proofing supporting members mounted on the said troughlikelower casing portion which is attached to the cylinder block by means ofsaid sound-proofing supporting members, a cavity defined by the casingand the outer surfaces of the engine, two chambers sealed off againsteach other within said cavity, the first of said chambers being enclosedby said troughlike lower casing portion and oil-wetted, the second ofsaid chambers being surrounded by said upper casing portion and keptfree from oil and auxiliary machines arranged on the engine within saidsecond chamber.
 2. An internal combustion engine as in claim 1, whereinsaid bottom portion terminates approximately on the same level as theupper edge of the cylinder head, with the directly adjoining said coverbeing essentially flat.
 3. An internal combustion engine as in claim 1,wherein said bottom portion of the casing and said upper portion of thecasing each are made of one piece.
 4. An internal combustion engine asin claim 6, wherein said bottom portion of the casing and said upperportion of the casing are made of synthetic material.
 5. An internalcombustion engine as in claim 1, wherein said bottom portion of thecasing comprises a number of structural elements interconnectedinseparably and in a manner providing an oiltight seal.
 6. An internalcombustion engine as in claim 5, wherein said structural elements aretightly interconnected by welding.